1. Field of Invention
The invention relates to emergency escape arrangements for an elevator and more particularly to such an emergency escape apparatus for an elevator with improved characteristics.
2. Related Art
Elevators are requisite equipment for high rise buildings. It is known that an elevator is required to incorporate a safety device in order to satisfy stringent safety requirements and stricter safety codes.
One typical safety device is brake which is provided between a car and a car guide rail. The brake is adapted to stop the car from falling freely in case of emergency such as power outage or overspeed of the car because of faulty speed regulation. Typically, should an emergency situation arises and after activating the brake, an elevator technician is called to go to a panel room to manually activate a drive sheave to lift or lower a car to a desired floor. Thereafter, reset the brake and thus return the elevator to its ready state. However, this procedure is very inconvenient. Further, it involves technician. Unfortunately, this is not practical since all persons trapped in an elevator car may have died before an elevator technician arrives. Furthermore, after activating the brake, a main motor may rotate without load due to insufficient friction between hoist ropes and a drive sheave. In addition, conventional elevators rely on the main motor as drive source (i.e., no backup motor). This means that escape is impossible in case of power outage or the main motor malfunctioning. Thus, a need for improvement still exists.